Tom McCasland, the authority's executive director, said the shift, approved on Wednesday, simply continues a growing local focus on homelessness. The housing authority targeted its vouchers in a similar way last November.

Also on Wednesday, Mayor Annise Parker appointed her first special assistant for homeless initiatives.

"Everyone who's working on this issue is very excited about the coordination that's happening, as well as the resources that are being brought to bear on this very fixable problem," McCasland said. "It's a matter of going out there, providing them the supportive services they need and putting them into housing, and we can do that far cheaper than the current system, where we use law enforcement and emergency health care services to take care of this population on the street."

McCasland expects to issue 600 vouchers to those on its waiting list this year.

The first 100, he said, will go to homeless families with school-age children, and the next 20 will go to formerly homeless individuals who have been stabilized through a Harris County supportive housing program. The rest of the available vouchers will go to working families, seniors and disabled residents at 30 percent of the area median income or below.

The agency's preferences coming into Wednesday's meeting had focused on moving hurricane victims from disaster programs into the rental voucher program.